In the field of chemistry, a mole is defined as the amount of a substance that contains exactly 6.02214076 * 10 23 ‘elementary entities’ of the given substance. The number 6.02214076*10 23 is popularly known as the Avogadro constant and is often denoted by the symbol ‘N A ’. The elementary entities that can be represented in moles can be atoms, molecules, monoatomic/polyatomic ions, and other particles (such as electrons). For example, one mole of a pure carbon-12 ( 12 C) sample will have a mass of exactly 12 grams and will contain 6.02214076*10 23 (N A ) number of 12 C atoms. The number of moles of a substance in a given pure sample can be represented by the following formula: n = N/N A Where n is the number of moles of the substance (or elementary entity), N is the total number of elementary entities in the sample, and N A is the Avogadro constant. The word “mole” was introduced around the year 1896 by the German chemist Wilhelm Ostwald, who derived the term from the Latin word moles meaning a ‘heap’ or ‘pile. (i) How many moles of iron are present in a pure sample weighing 558.45 grams? a) 10 moles b) 20 moles c) 30 moles d) 5 moles (ii) How many grams of carbon can be found in 1 mole of carbon dioxide? a) 1 g b) 5g c) 12 g d) 14 g